The G3 is a sniper rifle with a difference - a 3-round burst of fire. It has medium-low damage, medium-low range, medium-fast rate of fire, medium-high ammo and medium accuracy compared to other sniper rifles. Because of all this, the G3 is a well balanced weapon, especially useful against medium armoured enemies.
Recommended use with: Overkill skill. With that, you'll be able to kill enemies quicker. You can also use Wall Hack to great effect with this weapon. Also, if you have an Automag, a Desert Eagle, or a MP9, they are highly recommended to use. First, shoot an enemy. If he doesn't die, use the Automag/Desert Eagle/MP9 to finish him off. That enemy will also need a few shots to die, so this way you can use those (Automag/Desert Eagle/MP9) two weapons in the right way.
Recommended use against: All enemies. This weapon is great in finishing off big crowds in about 10 seconds.